Fire retardant polyisocyanurate and polyurethane foams having reduced smoke levels and method for producing same

Abstract

This invention relates to fire-retardant polyisocyanurate and polyurethane foams having reduced smoke levels when burned and to methods for producing such foams. The foams are produced by incorporating into the polyisocyanurate or polyurethane A. polycarboxylic cycloaliphatic acids having 3 non-adjacent carboxylic acid groups or any configuration with more than 3 carboxylic acid groups up to and including acids containing one carboxylic acid group per carbon atom, B. polycarboxylic heterocycloaliphatic acids having 3 non-adjacent carboxylic acid groups or any configuration with more than 3 carboxylic acid groups up to and including acids containing one carboxylic acid group per carbon atom, C. polycarboxylic aromatic acids having 3 non-adjacent carboxylic acid groups or any configuration with more than 3 carboxylic acid groups up to and including acids containing one carboxylic acid group per carbon atom, D. polycarboxylic naphthalenic acids having 3 non-adjacent carboxylic acid groups or any configuration with more than 3 carboxylic acid groups up to and including acids containing one carboxylic acid group per n-2 carbon atoms, where n = total number of carbon atoms in the ring system. Some anhydride groups may also be present in the composition.

What is claimed is: 
     
       1. Polyisocyanurate and polyurethane foams characterized by reduced smoke levels when burned comprising a foam material selected from the group consisting of polyisocyanurate and polyurethane foams, and   an acid incorporated in said foam in an amount sufficient to reduce smoke levels of said foam when said foam is burned, said acid being selected from the group consisting of   a. polycarboxylic cycloaliphatic acids having 3 non-adjacent carboxylic acid groups or any configuration with more than 3 carboxylic acid groups up to and including acids containing one carboxylic acid group per carbon atom,   b. polycarboxylic heterocycloaliphatic acids having 3 non-adjacent carboxylic acid groups or any configuration with more than 3 carboxylic acid groups up to and including acids containing one carboxylic acid group per carbon atom,   c. polycarboxylic naphthalenic acids having 3 non-adjacent carboxylic acid groups or any configuration with more than 3 carboxylic acid groups up to and including acids containing one carboxylic acid group per n-2 carbon atoms, where n = total number of carbon atoms in the ring system, and   d. mixtures of said acids.   
     
     
       2. The foam composition of claim 1 wherein said acid is present in an amount of from about 5 to about 40% by weight of said composition. 
     
     
       3. The foam composition of claim 1 wherein said acid is present in an amount of from about 10 to about 20% by weight of said composition. 
     
     
       4. The foam composition of claim 1 wherein said acid is 2,3,4,5-tetrahydrofuran-tetracarboxylic acid. 
     
     
       5. The foam composition of claim 1 wherein said acid is 1,4,5,8-naphthalene tetracarboxylic acid. 
     
     
       6. The foam composition of claim 2 wherein said acid is 2,3,4,5-tetrahydrofuran-tetracarboxylic acid. 
     
     
       7. The foam composition of claim 2 wherein said acid is 1,4,5,8-naphthalene tetracarboxylic acid. 
     
     
       8. The foam composition of claim 3 wherein said acid is 2,3,4,5-tetrahydrofuran-tetracarboxylic acid. 
     
     
       9. The foam composition of claim 3 wherein said acid is 1,4,5,8-naphthalene tetracarboxylic acid.